This invention relates to a method of producing improved match head compositions and the resulting compositions per se. In particular it relates to the in-situ bleaching and curing, i.e. cross-linking, of animal glues or colored gelatins employed as binders in match head compositions.
Match head compositions are generally characterized as pyrotechnic mixtures of an igniting agent, combustible material, a binder and various amounts of other ingredients such as oxidizers, fillers, dispersants, colorants, etc. While all the major ingredients of said compositions are considered important, the binder or glue which holds the mixture together has always been considered one of the more important and complex parts of a match head composition. Not only does the binder hold the mixture together, it also contributes to the stability of the wet match head compositions and the hardness and moisture resistance of the final match head.
Traditionally, the binder or adhesive used in match head compositions has been a collagen known as animal hide glue. While there are many grades of animal hide glues, the higher quality glues, i.e. the more expensive glues, are predominant in that they possess the higher molecular weights and viscosities which result in better adhesive properties. By employing an in-situ procedure for bleaching and curing, all animal glues, including hide glue and bone glue, achieve a higher molecular weight and increased viscosity thus permiting the use of colored gelatin which is a by-product of the manufacture of gelatin medicine capsules.
Accordingly, it is an object of the present invention to provide a match head composition which is improved by the use of in-situ processing-enhanced animal glues or colored gelatin which improves the physical and chemical properties to the pyrotechnic mixture.
It is another object of the present invention to provide a method of bleaching or bleaching and cross-linking animal glues or colored gelatin in situ so as to provide a pyrotechnic mixture of improved physical and chemical properties.
It is a further object of the present invention to provide a match head composition with no or reduced levels of potentially environmentally hazardous cross-linking agents such as hexavalent chromium ions, i.e. potassium dichromate.
It is a further object of the present invention to reduce the hexavalent chromium ion to the trivalent chromium ion in situ through the addition of sodium dithionite. Said trivalent chromium ion is a cross-linking agent for animal glues and colored gelatin.
Other objects and advantages of the present invention will become more apparent when considered in light of the following discussion.